I did a video series showing how you can use the app, the schematics you can follow, and also put a code example, youtube video playlist: https://bit.ly/34qoYDY
This app can be used to establish wireless communication between our smartphone and the ESP32 microcontroller.
We can use the app to send voice commands to the board, but also we can send written commands to it.
I have some other ideas to improve the app, I will be adding other input fields to be able to send different types of data to it, but also I will be adding components for displaying data sent by the board.
As we know ESP32 has Bluetooth and wifi built-in, so we don't need to use any other modules, I haven't tested the app with the Arduino board and the Bluetooth modules available, so if you have them, test it out.
The app uses Bluetooth Classic to communicate with the board, you will need to upload this code to the board: https://github.com/Zdravevski/talk-to-esp32
Everything is explained in the videos I posted.
Feel free to change the ESP32 code, and make it suitable for your needs, it is written just to demonstrate what can be done.
Have a nice time experimenting with this great board 😃